There has been known a web service employing an interface for displaying a plurality of images aligned. For example, there have been known a service for disclosing a cooking image contributed by a user together with its recipe, a service for disclosing an automobile image contributed by a user, and the like.
In displaying a plurality of images aligned in the above described service, a thumbnail image that is generated by trimming a part of an original image is often used. Conventionally, such a thumbnail image is often generated manually. In recent years, however, an increasing number of web services involving a large amount of such images come to be available, and accordingly, a technique for efficiently generating a large amount of thumbnail images is strongly desired.
As such a technique, there has been known a technique for automatically generating a thumbnail image from an image by trimming at a predetermined fixed position, for example.
Patent Literature 1, for example, discloses trimming so as to generate a trimming image showing a key object that is selected by a user and that is positioned at the center.